Method for producing and magazining individual magnetic components and the assembly thereof for producing miniaturized magnetic systems and such magnetic systems

ABSTRACT

The object of the invention is to produce multipole magnetic systems that are composed of a plurality of individual magnetic components that preferably are made of rare-earth magnetic material. The invention relates to a method for producing and magazining at least one individual magnetic component, a magazine for at least one individual magnetic component by molding and for conventionally magnetizing the same. The invention further relates to a method of assembly for producing a magnetic system and to the resulting magnetic systems. The invention teaches that extremely flat multipole magnetic systems in the form of magnet rings or magnet strips and three-dimensional magnet bodies such as a magnetic scale, for example, can be produced by means of individual magnetic components that are directly adjacent to each other or are arranged at a distance by means of a molding material, for example. The magnetic systems taught by the invention are provided with a particularly high level of integration of the individual magnetic components and a uniform overall magnetization of the magnet segments which, acting as permanent magnet components, can be used in electromagnetic drives, magnetic path and angle measuring systems, magnetic couplings and valves, for example.

FIELD OF THE INVENTION

This invention relates to the manufacture of multipole magnetic systemsthat are comprised of a plurality of individual magnetic components. Forthis purpose, a method is indicated for the manufacture by molding andmagazining of at least one individual magnetic component, a magazine forat least one individual magnetic component and its magnetization, anassembly method for the manufacture of a magnetic system and theresulting magnetic systems, such as, for example, a magnet ring, amagnet strip and a magnetic scale.

BACKGROUND OF THE INVENTION

Magnetic systems of the type described above are used, for example, inelectromagnetic drives, such as permanent and hybrid drives, in magneticdistance and angle measurement systems, in magnetic couplings and valvesand in magneto-sensitive sensors. In the course of miniaturization,these systems must be made smaller and smaller while achieving similarperformance, or they must retain the same size while achievingever-increasing performance. On one hand, magnetic systems are requiredthat can be adapted visually to the measurement systems or thefunctional geometry of these systems. These systems can be both flat,two-dimensional magnetic films as well as magnet systems with a complexthree-dimensional external shape. On the other hand, high-outputmagnetic materials such as rare-earth magnetic materials, in particularNdFeB, are being used. The advantage of NdFeB magnetic systems is thateven at low magnetic film thicknesses, a high magnetic actuation andhigh B-field can be achieved in the magnetic circuit. NdFeB has a highmagnetic hardness and a low demagnetization. Furthermore, a uniformoverall magnetization of the magnet segments is desirable, to achievethe sharpest possible transition between two neighboring, oppositelypolarized magnetic segments.

A disadvantage with the use of NdFeB magnetic systems is that magneticfield strengths of up to more than 500 kA/m and correspondingly highmagnetization currents must be used for the production of the magneticsegments. In conventional magnetization devices, the magnetization ofthese magnetic systems is realized in a process by means of pulsemagnetization with a short heavy current pulse by a magnetizer coil thatis specially adapted to the magnetic system A disadvantage of thismethod is that on account of the extremely high magnetization currents,correspondingly large line cross sections are necessary for the coils,and that is a limiting factor for the distance between pole centers andthus for the integration density of the magnets. By means of thismethod, it becomes possible to manufacture magnetic systems withstrip-shaped, multipole magnetization and distances between pole centersof 2 or 1 mm.

For example, as described in the publication “Micromachining andMicrofabrication” in Proc. SPIE Vol. 3680B-65, for the manufacture ofthe disc rotor motor and its rotor disc described in the two Germanpatent applications DE 199 02 370 and DE 199 02 371, a magnetic ring wasmanufactured by molding from NdFeB magnetic material. This ring was thenmultipole magnetized completely in a conventional pulse magnetizationdevice with a coil shaped to correspond to the magnetic segments to beformed. On one hand, magnetic field losses are found in the peripheralareas between two magnetic segments, and on the other hand, theconfiguration of the magnetic surface is already significantlyrestricted by the fact that almost no magnetization takes place in areasof the coil windings.

With conventional shapes of the magnetization coils, moreover,complicated shapes of magnetic systems cannot be magnetized in a singleprocess. As an alternative, the magnetic segments are producedindividually, whereby magnetization heads generate part of the requiredmagnetic field strength. A disadvantage of this method is that it is aserial process, and therefore requires a good deal of time to complete.Furthermore, to achieve the necessary saturation, a minimum distancemust be maintained between the magnetic head and the surface to bemagnetized, which is a limiting factor in the reduction of the distancebetween pole centers. Moreover, the very high forces that occur duringthe magnetization process place mechanical loads on the magnetizationheads, which means that the magnetization heads must be provided withcomplex retaining and support structures.

To eliminate the problems of the magnetization of miniaturized magneticsystems described above, DE 195 33 120 A1 and the correspondingpublication in the journal “Feinwerktechnik und Mikrotechnik,Mikroelektronik (FuM)” 105 (1998) 4, p. 194 ff., Carl Hanser Verlag, forthe formation of a magnetic position sensor, describe a magnetic disc ora code carrier and a method for its manufacture, whereby the codecarrier consists of two parts with a tooth structure on the periphery.The two parts are radially magnetized separately from each other, onepart with the magnetic north pole on the outside periphery and the otherpart with the south pole on the outside periphery. When the two partsare put together, the desired alternating magnetic field is formed. Onedisadvantage with this process is that to assemble the code carrier,molded joint structures are required, which in this case are in the formof tooth structures. These joint structures also limit the furtherminiaturization of the code carriers.

SUMMARY OF THE INVENTION

The object of the invention is therefore to significantly improve amultipole magnetic system consisting of a plurality of individualmagnetic components and a method for the manufacture of these individualmagnetic components, as well as a method for the assembly of theindividual magnetic components into such a magnetic system, so that anydesired distance between pole centers can be created accurately andreproducibly, whereby a conventional magnetization device can be used,and magnetic systems can be manufactured with directly adjacentindividual magnetic components. An additional object of the invention isto manufacture magnetic systems with retaining or joint structures thatdo not increase the height and size of the magnetic systems.

The invention teaches that the magnetic system to be fabricated ismanufactured from a plurality of individual magnetic components, wherebya method taught by the invention is used for the manufacture by moldingand magazining of at least one and preferably a plurality of individualmagnetic components, and the entire magazine with the individualmagnetic components is magnetized all at once in a magnetization device.The magazine is described by the characteristic features disclosedherein. Then the magnetized individual magnetic components are assembleddirectly from the magazine into a multipole magnetic system with twoassembly methods taught by the invention. The magnetic systemspreferably formed by these methods are also described herein below.

Additional objectives, advantages, features and possible applications ofthe Invention are explained in the following detailed description of anumber of different exemplary embodiments, with reference to theaccompanying drawings. All the features described and/or illustrated inthe figures, individually or in any reasonable and desired combination,are the object of the invention, regardless of their placement in theclaims or the reference numbers applied to them.

BRIEF DESCRIPTION OF THE DRAWINGS

In the figures:

FIG. 1 a) is a plan view from overhead, and b) is a section through amagnet ring composed of a plurality of individual magnetic components.

FIG. 2 a) is a plan view from overhead, and b) is a section through amagnet strip composed of a plurality of individual magnetic components.

FIG. 3 shows an additional embodiment of the magnet strip.

FIG. 4 a) is a plan view from overhead and b) is a section through amagnetic scale composed of two magnet strips as illustrated in FIG. 3.

FIGS. 5 a-d illustrate the manufacture by molding of the individualmagnetic components illustrated in FIGS. 1 to 4.

FIGS. 6 a-b illustrate the manufacture by molding of a magazine thatconsists of a support and individual magnetic components.

FIG. 7 a) is a plan view from overhead and b) is a section through amagazine as illustrated in FIG. 6 consisting of a support and individualmagnetic components.

FIG. 8 a) shows the axial and b) the diametrical simultaneousmagnetization of the individual magnetic components placed in themagazine as illustrated in FIG. 7.

FIG. 9 a) is a plan view from overhead and b) is a detail and c) asection through the detail of a magazine with individual magneticcomponents in the shape of segments of a circular ring magnetizedradially in the north-south pole direction.

FIG. 10 a) is a plan view from overhead and b) is a detail and c) asection through the detail of a magazine with individual magneticcomponents in the shape of segments of a circular ring magnetizedradially in the south-north pole direction.

FIG. 11 a) is a plan view from overhead and b) is a section through amagazine with rectangular solid individual magnetic componentsmagnetized axially in the south-north pole direction.

FIG. 12 is a section through an additional embodiment of the magazinewith rectangular solid individual magnetic components magnetized in thesouth-north pole direction, whereby a magnet surface is manufactured.

FIG. 13 is a plan view from overhead of a detail of an additionalembodiment of a magazine with rectangular solid individual magneticcomponents and recesses magnetized axially in the north-south poledirection.

FIG. 14 is a section through a detail of an additional embodiment of amagazine with rectangular solid individual magnetic components andrecesses magnetized axially in the north-south pole direction.

FIG. 15 shows assembly robots for the multiple assembly of multipolemagnetic systems.

FIG. 16 shows the assembly of a plurality of magnetic rings asillustrated in FIG. 1 on an assembly plate with two magazines withindividual magnetic components as illustrated in FIGS. 9 and 10.

FIG. 17 shows the assembly of a magazine with a plurality of magneticrings illustrated in FIG. 1 with a magazine with individual magneticcomponents and recesses and a magazine with individual magneticcomponents as illustrated in FIG. 10.

FIG. 18 shows a magazine with a plurality of magnet rings as illustratedin FIG. 1.

FIG. 19 illustrates the assembly of magnet rings as illustrated in FIG.1 on an assembly plate with a magazine with individual magneticcomponents.

FIG. 20 illustrates the assembly of a magnet strip as illustrated inFIG. 2 on an assembly plate from two magazines as illustrated in FIG.13.

FIG. 21 illustrates the assembly of a magnet strip as illustrated inFIG. 2 with one magazine as illustrated in FIG. 11 and one magazine asillustrated in FIG. 13.

FIG. 22 illustrates the assembly of a magnetic scale as illustrated inFIG. 4 with two magazines as illustrated in FIG. 11.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 a shows a plan view from overhead and FIG. 1 b shows a sectionthrough a multipole magnet system 3 in the form of a magnet ring 4assembled from a plurality of magnetized individual magnetic components1, 2.

The individual magnetic components 1, 2 in the exemplary embodimentselected here, which can be accurately and reproducibly manufacturedusing an injection compression method, are both made of a magnetizableand moldable permanent magnetic material, such as plastic-bonded NdFeBmaterial, for example. The use of plastic-bonded NdFeB material makespossible the molding of thin-walled or flat shapes of the individualmagnetic components 1, 2. The individual magnetic components 1, 2 havethe external shape 52 of the segments of a circular ring, and asillustrated in FIG. 1 are arranged in the magnet ring 4 alternately anddirectly adjacent to each other. The thickness of the magnet ring 4 isapproximately 300 μm. It would also be possible to use othermanufacturing molding methods, such as injection molding or compressionmolding, for example. Moldable SmCo, such as plastic-bonded SmCo, forexample, can also be used as the magnetic material. The individualmagnetic components 1, 2 can also be made of magnetic materials with alow remanent induction, such as hard ferrites on a strontium or bariumbasis, for example, or a magnetizable material with a low coercive fieldstrength such as AlNiCo, for example.

The invention teaches that the individual magnetic components 1, 2 aremagnetized in a conventional magnetization device as illustrated in FIG.8 by means of pulse magnetization along their longitudinal andtransverse dimension. The individual magnetic components 1, 2 are bothaxially magnetized, and in particular so that the individual magneticcomponents 1 are magnetized in the north-south pole direction, which isanother way of saying that the individual magnetic components 1illustrated in FIG. 1 c have a north pole on the one end surface 5 a anda south pole on the other end surface 5 b. The individual magneticcomponents 2 are correspondingly polarized axially in the oppositesouth-north pole direction, i.e. they have a south pole on the endsurface 5 a and a north pole on the end surface 5 b. Consequently, themagnet ring 4 assembled from the individual magnetic components 1, 2 isan 8-pole assembly on both end surfaces 5 a, 5 b and therefore has 4pairs of poles.

The magnet ring 4 is used as the rotor disc in a DC disc rotor motor asdescribed in one of the two patent applications DE 199 02 370 and DE 19902 371. As a result of the extremely flat vertical dimension of themagnet ring 4, the disc rotor motor has a vertical dimension of only 1.4mm with an outside diameter of 12.8 mm. The torque constant of the motoris approximately 0.40 μNm/mA. The motor can be used without furthermodification for speeds of rotation of up to 20,000 min⁻¹ with very highfreedom from vibration.

In general, the molding manufacture of the individual magneticcomponents taught by the invention and their separate magnetization canbe used to accurately and reproducibly manufacture any desired distancebetween pole centers. In addition, the magnet ring 4 has no largesupport or retaining structures. This arrangement makes possible thefurther miniaturization of systems in which the magnet ring 4 is used,such as, for example, electromagnetic drives, including hybrid steppermotors and disc rotor motors. In this regard, reference is made to thearticle entitled “Kleine Kraftpakete—Strukturierte dünneMagnetschichten” [Small Power Packets—Structurable thin magnetic films]in the journal F&M 107 (1999) 4, p. 24 ff, and to the article entitled“Optimierte Magnete für Hybridschrittmotoren” [Optimized magnets forhybrid stepper motors] in F&M 106 (1998) 7-8 p. 503 ff., both publishedby Carl Hanser Verlag.

FIG. 2 a shows a plan view from overhead and FIG. 2 b shows a sectionthrough a multipole magnet system 3 in the form of a magnet strip 8 madeup of a polarity of magnetized individual magnetic components 6, 7. TheIndividual magnetic components 6, 7 have a rectangular solid outer shape52 and are arranged alternately and directly adjacent to one another inthe magnet strip 8. The thickness of the magnet strip 8 is approximately300 μm. The individual magnetic components 6, 7 are both axiallymagnetized, whereby the individual magnetic components 6 have a northpole on the end surface 9 a of the magnet strip 8 illustrated in FIG. 2and the individual magnetic components 7 have a south pole.Consequently, the magnet strip is polarized on the end surface 9 a aswell as on the end surface 9 b with 19 poles with north and south polesin alternation. This magnet strip 8 formed from permanent magnets ofalternating polarity can be used as a permanent magnet component inmagnetic distance measurement systems, for example, in an embodimentdesigned to take measurements of length.

FIG. 3 is a section through an additional exemplary embodiment of themagnet strip 8 formed from permanent magnets of alternating polarity. Incontrast to the embodiment illustrated in

FIG. 2, the individual magnetic components 6, 7 are located next to oneanother by a carrier 10. The carrier 10 is made of a molded material 34and in the exemplary embodiment illustrated here is made of atwo-component molding resin. Another preferred carrier material is athermoplastic or elastomer plastic. As illustrated in FIG. 3, thecarrier 10 or the molded material 34 encompasses the individual magneticcomponents 6, 7 on their lateral surfaces 16 a, b and 17 a, b in apositive or form-fitting manner, and molding material 34 is locatedbetween each two neighboring individual magnetic components 6, 7. Inthis embodiment, the individual magnetic components 6, 7 are keptseparate from one another by the carrier material, so that magnetsystems 3 with a greater distance between pole centers can bemanufactured. The carrier material arranged in this manner also performsa supporting and retaining function between each two individual magneticcomponents 6, 7 and thereby improves the mechanical stability of themagnet strip 8, although without increasing its height. The necessarymechanical stability of this magnet strip 8 is further improved by thefact that the carrier 10 is also realized so that it acts as aform-fitting outer enclosure 18 for the individual magnetic components6, 7. The external shape of the enclosure 18 can therefore be a circle,a strip or a similar shape.

FIG. 4 a is a plan view from overhead and FIG. 4 b is a section througha magnetic scale 12 that is put together from two magnet strips 8 a, b.The magnet strip 8 a illustrated in FIG. 4 b, in contrast to the magnetstrip 8 illustrated in FIG. 3, has individual magnetic components 7 thatare magnetized only in the south-north pole direction, and are locatedat some distance from one other by the carrier 10 made of moldingmaterial 34. In the same manner, individual magnetic components 6magnetized in the north-south pole direction are assembled into themagnet strip 8 b. The magnetic scale 12 illustrated in FIG. 4 b consistsof the two magnet strips 8 a and 8 b located one on top of the other,whereby the individual magnetic components 7 can be arranged so thatthey are laterally offset with respect to the individual magneticcomponents 6, so that the magnetic scale 12 has alternating polarity onthe two end surfaces 13 a, b. In the exemplary embodiment illustratedhere, the magnetic scale 12 illustrated in FIG. 4 a in an overhead planview has south poles of the individual magnetic components located nextto each other in the magnet strip 8 a of the end surface 13 a, andbetween them, as shown in the sectional view, north poles of theindividual magnetic components 6 located in the magnet strip 8 b. As aresult of this arrangement of the individual magnetic components 6, 7,the magnetic scale 12 generates an alternating magnetic flux along theend surface 13 a. Thus the magnetic scale 12 can be coupled in arotationally symmetrical shape to a motor shaft and act as a decoder. Onthe other hand, the magnetic scale 12 can also be used in a linearactuator to embody the longitudinal dimension, and thus provide a lengthmeasurement. In the exemplary embodiment illustrated in FIGS. 4 a and 4b, the two ends 14 a, 14 b of the magnetic scale 12 can be realized inthe form of non-magnetizable carrier material in the form of a step 15.These steps 15 make possible a lateral gripping of the magnetic scale12, without having to come into contact with the individual magneticcomponents 6, 7. Of course, the two ends 14 a, b of the magnetic scale12 can also be realized in the form of perpendicular ends without a step15.

FIGS. 5 a to 5 d illustrate an injection compression process as apreferred method for the manufacture of the individual magneticcomponents 1, 2, 6, 7 as illustrated in FIGS. 1 to 4. FIG. 5 a is aschematic illustration of the structure of an injection compression tool19. The injection compression tool 19 has an upper tool half 20 and alower tool half 21, each of which has a closing stop 22 a, b. In theopen position of the injection compression tool 19 shown in FIG. 5 a,the two dosing stops 22 a, b are separated from each other. To mold aplurality of individual magnetic components 1, 2, 6, 7 on a base plate23, as illustrated in FIGS. 5 b to 5 d, the upper tool half 20 has amold insert 24 that has a plurality of cavities 25. The bottom tool have21 has for this purpose a gate channel 27 with a conically shapedinjector tip 28 and an injection nozzle 29 for the injection or chargingof a magnetizable material 26 into the mold insert 24, as illustrated inFIGS. 5 a, b. The injection nozzle 29 is oriented centrally with respectto the injection tip 28 and to the mold insert 24. As shown in FIG. 5 a,the magnetizable material 26 is first placed in the mold insert 24 inthe form of a bubble 30.

In the closed position of the tool 19 illustrated in FIG. 5 b, thebottom tool half 21 fits into the top tool half 20 until the two closingstops 22 a, b come into contact with each other. On one hand, thiscauses the magnetizable material 26 to be pressed into the cavities 25.On the other hand, the injection nozzle 29 penetrates into the injectortip 28 and seals it off. This makes possible a small-volume casting anda defined separation of the magnetizable material 26 from the base plate23 molded in the mold insert 24.

One very special teaching of the invention is that the arrangementspecified for the manufacture by molding of the individual magneticcomponents 1, 2, 6, 7 using the mold insert 24 is transferred to thearrangement of the individual magnetic components 1, 2, 6, 7 on the baseplate 23. Consequently, this arrangement and thus the fixed position ofthe various individual magnetic components 1, 2, 6, 7 with respect toone another is retained for the entire rest of the processing andhandling of the individual magnetic components 1, 2, 6, 7, namely forthe manufacture by molding of a magazine 40 with individual magneticcomponents 1, 2, 6,7, the magnetization and assembly of which into amagnet system 3 are retained, for example when they are assembled into amagnet ring 4 or a magnet strip 8. In this regard, FIG. 5 c shows asectional view and FIG. 5 d a plan view from overhead of the base plate23 unmolded from the injection compression tool 19 with a plurality ofindividual magnetic components 1, 2 in the form of segments of acircular ring located on it. As illustrated in FIG. 5 d, the base plate25 is realized in the external format of a wafer 31 with a dimension of3, 4, 5 or 6 inches, for example. This teaching makes it possible to usethe handling and transport technology of the semiconductor industry.

A further special teaching of the invention is that the individualmagnetic components 1, 2, 6, 7 on the base plate 23, oriented as shownin FIG. 5 d, are already arranged in groups 32, so that after they havebeen magazined and magnetized in this group arrangement, they can beassembled directly into a magnet system 3.

FIGS. 6 a and 6 b show the manufacturing by molding of a magazine 40that consists of a carrier 10 and individual magnetic components 1, 2,6, 7. FIG. 6 a shows a two-component injection molding method as apreferred method for the manufacture by molding of the magazine 40 withindividual magnetic components 1, 2, 6, 7 as illustrated in FIGS. 1 to4. As illustrated in FIG. 6 a, first the base plate 23 with theindividual magnetic components 1, 2 located on it is set with an excessborder on the side in a molding tray 33. Then the individual magneticcomponents 1, 2 are inserted from above with the two-component moldingresin 34 that forms the carrier 10 and hardens. As a result of thisprocess, the arrangement defined by the mold insert and transferred tothe base plate 23 and the fixed position of the individual magneticcomponents 1, 2, 6, 7 with respect to one another is retained in themagazine 40. After the resin 34 has set, the base plate 23 with theindividual magnetic components 1, 2, molded onto it are removed from themolding tray 33 and, as shown in FIG. 6 b, are placed on a vacuumholding plate, to remove the flashing 36 of the resin 34 that extendsbeyond the individual magnetic components 1, 2 and the base plate 23 bymilling.

Alternatively, the individual magnetic components 1, 2, 6, 7 and themagazine 40 can also be manufactured using a two-component injectionmolding process. For that purpose, the injection mold used is preferablyof the type illustrated in FIGS. 2 to 4 of Patent Application DE 199 26181. In general, it thereby becomes possible for the sequence ofmanufacturing operations of the magazine 40 and of the individualmagnetic components 1, 2, 6, 7 to be selected as desired, depending onthe configuration of the individual magnetic components and of themagazine. Thus the magazine 40 can be manufactured first and then theindividual magnetic components 1, 2, 6, 7, for example in twoimmediately successive molding processes. Consequently, both the baseplate 23 used during the two-component molding process and themechanical post-treatment illustrated in FIG. 6 b are no longernecessary for the manufacture of the magazine 40.

FIG. 7 a is a plan view from overhead and FIG. 7 b is a section throughthe magazine 40 manufactured in the manner described above with aplurality of individual magnetic components 1, 2. The individualmagnetic components 1, 2 in the embodiment of the magazine 40illustrated here are encompassed in a form-fitting manner by the moldingmaterial 34 on all their lateral surfaces, i.e. there is also moldingmaterial 34 between two neighboring individual magnetic components 1.2.As a result of this embodiment, it is possible to realize a flatmagazine 40 that has the same height as the individual magneticcomponents 1, 2 with a plurality of individual magnetic components 1, 2,6, 7 made of plastic-bonded NdFeB material. The comparison with FIG. 5 calso shows that the arrangement of the individual magnetic components 1,2 in groups 32 is also retained In the magazine 40. The advantage isthat the individual magnetic components 1, 2 now need only be surroundedby the molding material 34 on their lateral surfaces 37 and do not, asin FIG. 5 c, sit on the base plate 23, and further that the individualmagnetic components 1, 2 can therefore be removed from the magazine 40for assembly simply by pushing them out of the magazine 40.

FIG. 8 shows a conventional magnetization device 38 with largemagnetization coils 39 of the type used for the magnetization of all theindividual magnetic components 1, 2, 6, 7 put together in the magazine40 as shown in FIG. 7. The special advantage of this magnetization astaught by the invention is that all the individual magnetic components1, 2, 6, 7 in the magazine 40 can be magnetized with a specifiedpolarization together and simultaneously with one coil, and specificallyregardless of the shape of the individual magnetic components 1, 2, 6,7. Furthermore, with an appropriate sizing of the magnetization coils39, only the individual magnetic components 1, 2, 6, 7 located in anarea of the magazine 40, such as in one half of the magazine 40, can bemagnetized in the same direction. It thereby becomes possible that in anoverhead view of a magazine 40, one half of the magazine 40 has northmagnetic poles and the other half of the magazine 40 has south magneticpoles. FIG. 8 shows an axial magnetization of all the individualmagnetic components 1, 2, 6, 7 in the magazine 40, so that theindividual magnetic components are magnetized with opposite polarity onthe two end surfaces. FIG. 8 b shows a diametrical magnetization of allthe individual magnetic components 1, 2, 6, 7 in the magazine 40, sothat the individual magnetic components 1, 2, 6, 7 can be magnetizedwith opposite polarity on their facing lateral surfaces. The particularadvantage of this magnetization taught by the invention of theindividual magnetic components 1, 2, 6, 7, which correspond to themagnet segments in the magnet system 3 to be formed, is that, comparedto a magnetization of a complete magnet system 3, such as for examplethe magnet ring 4 in FIG. 1, the individual magnetic components 1, 2, 6,7 can be completely magnetized all the way through. This prevents, amongother things, a decay of the magnetic field in the peripheral areas ofthe individual magnetic components 1, 2, 6, 7. Consequently, themagnetic field decay in the neighboring magnet segments in the magnetsystem 3 is determined only by the combination of the oppositelymagnetized individual magnetic components 1 and 2 or 6 and 7. Inaddition, a further miniaturization of the magnet systems 3, 4, 8, 12 tobe formed with the individual magnetic components 1, 2, 6, 7 becomespossible, because even extremely small individual magnetic components 1,2, 6, 7, manufactured by molding can be completely magnetized.

FIGS. 9 to 13 show various embodiments of the magazine 40 with theindividual magnetic components 40 assembled inside them, whichcorrespond to the magnetic segments in the magnet system 3 to be formed.

FIG. 9 a Is a plan view from overhead and FIG. 9 b is a detail, and FIG.9 c is a section through said detail of a magazine 40 with a pluralityof circular ring-shaped individual magnetic components 1 to bemagnetized axially, when viewed from overhead, in the north-south poledirection. FIG. 10 repeats the illustration in FIG. 9, although FIG. 10shows a magazine 40 with a plurality of circular ring-shaped individualmagnetic components 2 to be magnetized axially, when viewed fromoverhead, in the south-north pole direction. A comparison of theorientations of the individual magnetic components 1 in FIG. 9 with theindividual magnetic components 2 in FIG. 10, in particular in theenlarged details shown in FIG. 10 b and FIG. 9 b, shows that theindividual magnetic components 1, 2 are each arranged in groups 32 sothat they are complementary to each other and are arranged in a circularring, so that they can then be assembled directly into a multipolemagnet ring 4 as illustrated in FIG. 1. FIGS. 9 c and 10 c show theaxial magnetization of the individual magnetic components 1, 2 locatedin the group 32.

FIG. 11 a shows a plan view from overhead and FIG. 11 b shows a sectionthrough a magazine 40 with individual magnetic components 7 in the shapeof a rectangular solid that are magnetized axially in the south-northpole direction. In this exemplary embodiment, the individual magneticcomponents 7 are located at some distance from one another in themagazine 40, so that between two neighboring individual magneticcomponents 7, there is the carrier 10 or molding material 34. Moreover,10 individual magnetic components 7 are arranged parallel to one anotherin a magnet strip 8 a as illustrated in FIG. 4 b. The magazine 40 has,around each magnet strip 8 a, a rectangular frame 18′ made ofmagnetizable material 26 located around the individual magneticcomponents. This arrangement of the frame 18′ makes it possible for themagnet strip 8 a to be removed from the magazine 40 as a unit, i.e. withall 10 individual magnetic components 7. After the removal of the magnetstrip 8 a from the magazine 40, the frame 18′ which is conventionallymade of magnetizable material 26 is detached from the magnet strip 8 a,so that then the individual magnetic components 7 can be assembled by aframe 18 made of molding material 34. The magnet strip 8 a can be used,among other things, to manufacture magnet systems 3 with a greaterdistance between pole centers or even multilayer magnetic film systems3, such as the magnetic scale 12 illustrated in FIG. 4 by way ofexample. As shown in FIG. 11 b, the molding material 34 encompasses theindividual magnetic components 7 in the exemplary embodiment illustratedhere on their lateral surfaces in a form-fitting manner, so that thecarrier 10 and the individual magnetic components 7 are realized withthe same vertical dimension. An additional embodiment, not shown in theillustration, of the magazine 40 with individual magnetic components 1,2, 6, 7 has the molding material 34 encompassing the individual magneticcomponents 1, 2, 6, 7 at least on parts of their outside surfaces, suchas, for example, on at least parts of their end surfaces, so that it canact as a carrier 10. The individual magnetic components 1, 2, 6, 7 aretherefore covered with molding material 34 to protect at least parts oftheir end surfaces. This embodiment can be used preferably if instead ofthe individual magnetic components 1, 2, 6, 7, entire magnet systems 3,such as for example the magnet strip 8 a, are removed from the magazine40 to manufacture a magnetic scale 12, for example. The molding material34 on the end surface of an individual magnetic component 1, 2, 6, 7 canalso be realized in the form of a connecting means for the location ofan additional magnet strip, without thereby increasing the verticaldimension of the magnetic scale 12.

FIG. 12 shows a section of a detail of an additional embodiment of themagazine 40 with individual magnetic components 7 in the form of arectangular solid magnetized axially in the south-north pole direction.In this embodiment, in contrast to FIG. 11 b, the individual magneticcomponents 7 and the carrier 10 are manufactured with different heights.The purpose of this measure is to ensure that the carrier 10 ismanufactured only with parts of the lateral surfaces 17 a, b of theindividual magnetic components 7 in adhesive contact. This reducedadhesive contact facilitates the process of releasing the magnet strip 8a from the magazine 40. Moreover, in this embodiment of the magazine 40,the removal of the individual magnetic components 7 from the magazineduring the release process is also easier. For the manufacture of thisembodiment of the magazine 40, preference is given to the use of atwo-component injection molding process for the manufacture of thecarrier 10 and of the individual magnetic components 7. In general, thestructure of multipole magnet surfaces 3 forms a plurality of individualmagnetic components 7 arranged in an offset pattern is possible, asillustrated schematically in FIG. 12. To construct this magnet surface,for example, an additional individual magnetic component 6 is insertedbetween two individual magnetic components 7 that are next to oneanother and project out of the carrier 10. This method is repeated untila sufficiently large checkerboard-pattern magnet surface consisting ofnorth and south magnetic poles is manufactured.

FIG. 13 shows a plan view from overhead of an additional embodiment of amagazine 40 with rectangular solid magnetic components 6 magnetizedaxially in the north south pole direction and recesses 11. Compared tothe illustration in FIG. 11, this figure shows only a detail of themagazine 40 in the form of a magnet strip 8 c. In this magnet strip 8 c,only individual magnetic components 6 are arranged next to each other sothat between two individual magnetic components 6 there is a recess 11.The individual magnetic components 6 are held together by the carrier 10which is realized in the form of a strip-shaped frame 18.

FIG. 14 shows a section through an additional embodiment of a magazine40 with individual magnetic components 6 in the shape of a rectangularsolid magnetized axially in the north-south pole direction and recesses11, whereby only a portion of the magazine 40 is shown in the form of amagnet strip 8 d. In contrast to the magnet strip 8 d illustrated inFIG. 13, between each two individual magnetic components 6 in a rowthere is molding material 34, then a recess 11, and then moldingmaterial 34 again.

FIGS. 15 to 21 show various realizations of the assembly method claimedby the invention for the manufacture of a magnet system 3. The teachingcommon to all of these realizations is that to manufacture the magnetsystem 3, at least one magazine 40 is sued, and the individual magneticcomponents 1, 2, 6, 7 which correspond to the magnetic segments in themagnet system 3 to be formed, are positioned out of the magazine 40directly into the assembly position on a carrier 10, so that a multipolemagnet system 3, like the magnet ring 4, the magnet strip 8 or themagnetic scale 12, for example, is formed with alternating polarity onthe two end surfaces.

FIG. 15 shows an assembly robot 41 which is used for a particularlypreferred multiple assembly of the individual magnetic components 1, 2,6, 7 from the magazine 40 for the manufacture of the magnet system 3.For this purpose, the assembly robot 41, to press the individualmagnetic components 1, 2, 6, 7 out of the magazine 40 into the assemblyon the carrier 10, has an expulsion ram 51 with expulsion pins 51 a and,as a support for the magazine 40, a support plate 42. In the supportplate 42, directly underneath the expulsion ram 51, there is ananvil-like supporting ram 43. In the exemplary embodiment illustratedhere, the rotor disc of the disc rotor motor described in the two patentapplications DE 199 02 370 and DE 199 02 371 is being manufactured. Forthis purpose, in one preferred embodiment, first the individual magneticcomponents 1 magnetized in the north-south pole direction aretransported to the magazine 40 as illustrated in FIG. 9 from the supportplate 42, either by a feed table or by a conveyor belt. Then the carrier10 in the form of the motor cover 44 of the disc rotor motor is locatedon the expulsion ram 42 directly opposite underneath the magazine 40 ona guide bolt 45 of the anvil-like supporting ram 43.

Then the expulsion ram 51 is lowered, pneumatically for example, in thedirection indicated by the arrow in FIG. 15, and by means of theexpulsion pins 51 a, the entire group 32 of individual magneticcomponents 1 illustrated in the enlarged detail in FIG. 9 b is pushedout onto the motor cover 44. To prevent a tipping of the individualmagnetic components 1 after the individual magnetic components 1 havebeen detached from the magazine 40, the movement of the expulsion ram 51can be synchronized with a movement in the opposite direction by thesupporting ram 43 so that an expulsion of the individual magneticcomponents 1 becomes possible with the components being constantlyguided both positively and non-positively. Consequently, on the motorcover 44 a magnet ring 3 is formed, in which there is a space betweeneach two individual magnetic components 1. Then the expulsion ram 51 israised again and a magazine 40 of the type illustrated in FIG. 10 withindividual magnetic components 2 magnetized in the south-north poledirection Is guided to the support plate 42 and oriented so that theindividual magnetic components 2 arranged in groups 32 complementary tothe individual magnetic components 2 can be expelled directly into theremaining spaces of the magnet ring 3 on the motor cover 44. The motorcover 44 has an adhesive coating to fix the individual magneticcomponents 1, 2 in position. Finally the disc rotor, which consists ofthe motor cover 44 with the magnet ring 5 affixed to it, is removed fromunderneath the expulsion ram 51 and the next rotor disc is manufactured.

FIG. 16 illustrates and repeats the assembly process described abovefrom two magazines with individual magnetic components as illustrated inFIGS. 9 and 10 for the manufacture of a magnet ring 3 from FIG. 1. Inthis case, a preferably soft magnetic assembly plate 47 is used as thecarrier 10 to fix the individual magnetic components 1, 2 in position.The adhesive layer 46 can thereby be eliminated.

FIG. 17 shows another embodiment of the assembly method for themanufacture of magnet rings. In this case, a magazine 40 as shown inFIG. 9 is used with individual magnetic components 2 arranged in groups32. The carrier 10 is a magazine 40 with individual magnetic components1 arranged in groups, in which, as illustrated in FIG. 13, there is atleast one recess 11 between each two neighboring individual magneticcomponents. For the manufacture of the magnet ring 3, the individualmagnetic components 2 are pushed out by the expulsion pins 51 a of theassembly robot 41 directly into the recesses 11. The result, as shown inFIG. 18, is a magazine 50 which is made of hardened molding material 34,preferably two-component resin 34 a or plastic, which encompasses aplurality of magnet rings 3 consisting of individual magnetic components1, 2 at least on parts of one lateral surface.

FIGS. 19 a to c show the assembly of magnet rings 3 from FIG. 1 on asoft magnetic assembly plate 47, whereby only one magazine 40 is beingused. As shown in FIG. 19 a, this magazine 40, on the first half of themagazine 40 identified by the number 48, has only individual magneticcomponents 1 magnetized in the north-south pole direction, and on thesecond half identified by the number 49, only individual magneticcomponents 2 magnetized in the south-north pole direction. Using theassembly robot 41, first the individual magnetic components 1 located ina group 32 in the first half are expelled onto the assembly plate 47 andfixed in position. Then the magazine 40, as a comparison of FIGS. 18 aand 18 b shows, is rotated by 180°. Then the individual magneticcomponents 2 magnetized as shown in FIG. 18 b in the south-north poledirection and arranged in a group 2 are expelled onto the assembly plate47. As a result, a plurality of magnet rings, 3 are formed on theassembly plate 47, as shown in FIG. 19 c.

FIG. 20 shows the manufacture of a magnet strip 8 of the typeillustrated in FIG. 2. For this purpose, two magazines 40 as illustratedin FIG. 13 with, on one hand, individual magnetic components 6 arrangedin a magnet strip 8 c and magnetized in the north-south pole direction,and on the other hand individual magnetic components 7 arranged in amagnet strip 8 c and magnetized in the south-north pole direction arefed to the assembly robot 41 one after the other. First, by means of theexpulsion pins 51 a, all the individual magnetic components 6 are pushedout of the corresponding magnet strip 8 c onto the carrier, which is notshown here, and are fixed in position with an adhesive if necessary. Theresult is that first a magnet strip 8 is formed, in which a space islocated between two neighboring individual magnetic components 6. Thenthe individual magnetic components 7 are pushed out of the correspondingmagnet strip 8 c as illustrated in FIG. 13 onto the carrier (backing)and into these spaces. The result is the magnet strip 8 with individualmagnetic components 6, 7 lying directly next to each other, as shown inFIG. 20.

FIG. 21 shows that with a magnet strip 8 c as illustrated in FIG. 21 b,each of which has a recess 11 between two neighboring individualmagnetic components 7 and a frame 18 in the form of the carrier 10, itis possible to manufacture a multipole magnet strip 8 as illustrated inFIG. 21 c with individual magnetic components 6, 7 directly next to oneanother and an outer frame 18. For this purpose, the magnet strip 8 c inthe exemplary embodiment selected here and illustrated in FIG. 21 b hasa base plate 53. Individual magnetic components 6 arranged in a magnetstrip 8 b as shown in FIG. 21 a are then placed on this base plate 53and inserted in the recesses 11. Then the base plate 53 is removed, bymilling, for example, to form the multipole magnet strip 8 illustratedin FIG. 21 c with individual magnetic components 6, 7 lying directlynext to each other and the outer frame 18.

Finally, FIG. 22 illustrates the assembly of a magnetic scale 12 asshown in FIG. 4. For this purpose, two magazines 40 as shown in FIG. 11with the magnet strips 8 a, b in them, with on one hand individualmagnetic components 6 that are separated from one another by moldingmaterial 34 and are magnetized axially in the north-south poledirection, and on the other hand individual magnetic components 7arranged in a corresponding manner and magnetized axially in thesouth-north pole direction are used. The two magnet strips 8 a, b shownin FIG. 22 are located on one another as illustrated in FIG. 22 so thatthe individual magnetic components 7 are laterally offset from theindividual magnetic components 6, forming a magnetic scale 12 withalternating polarity on the two end surfaces 13 a, b.

The magnet strip 8 illustrated in FIG. 3 is manufactured by using amagazine 40 as illustrated in FIG. 14 with individual magneticcomponents 6, in which, between each two neighboring individual magneticcomponents 6 there is molding material 34, then a recess 11, and thenmore molding material 34. Then individual magnetic components 7 arepressed into these recesses 11. For this purpose, for example, amagazine 40 as illustrated in FIG. 11 with individual magneticcomponents 7 is used, in which the distance between two neighboringindividual magnetic components 7 is adapted to the distance between therecesses 11. The advantage of the manufacture as taught by the inventionof a magnet system 3 from a plurality of individual magnetic components1, 2, 6, 7 which are arranged in a magazine 40 with a fixed position inrelation to one another, is that extremely flat multipole magnet systems3 can be manufactured as illustrated in FIGS. 1 to 4. For example, thismethod can be used to manufacture extremely flat multipole magnet rings4 as illustrated in FIG. 1 or magnet strips 8 as illustrated in FIG. 2with individual magnetic components 1, 2 and 6, 7 respectively directlynext to each other. The particular advantage of these magnet systems 3is that no supporting or retaining structures need to be located betweenthe individual magnetic components 1, 2, 6, 7 that form the magnetsegments. As a result, a particularly high density of integration ofindividual magnetic components 1, 2, 6, 7 becomes possible in the magnetsystem 3 with almost any desired small distance between pole centers,whereby the invention teaches that only the assembly tolerance of theindividual magnetic components 1, 2, 6, 7 is a limiting factor in themanufacture of the magnet system 3. The invention teaches that thisassembly tolerance is already reduced to a very low amount, because onone hand the individual magnetic components 1, 2, 6, 7 are held in adefined position of the individual magnetic components 1, 2,6,7 withrespect to one another by the mold insert used in the molding portion ofthe manufacturing operation. On the other hand, the invention teachesthat the individual magnetic components 1, 2, 6, 7 are arranged ingroups with respect to one another so that they can be removed togetherin this group arrangement directly from the magazine 40 and assembledinto the magnet system 3. Thus the assembly tolerance is determined onlyby the precision of the transfer or the assembly of the individualmagnetic components 1, 2, 6, 7 out of the magazine 40 and into themagnet system 3. An additional general advantage of the invention isthat the individual magnetic components 1, 2, 6, 7 assembled in aplurality in a magazine 40 can be completely and simultaneouslymagnetized all the way through in a conventional magnetization device.As a result, in particular even losses that are caused during themultipole magnetization of a complete multipole magnet system, forexample a multipole magnet ring, can be prevented by superimposing thecoil windings of the magnetization device with the magnet segments.

The invention teaches that, with the individual magnetic components 1,2, 6, 7 claimed by the invention or the magazines 40 claimed by theinvention with individual magnetic components 1, 2, 6, 7, even extremelyflat multipole magnet systems 3 as illustrated in FIG. 3 can bemanufactured, in which between two neighboring individual magneticcomponents 6, 7 there is a carrier 10 made of molding material 34. Thiscarrier here is used only as a lateral support or retaining structure,whereby the height of the magnet system 3 is not thereby increased. As aresult of this arrangement of the carrier 0, a greater distance betweenpole centers of the individual magnetic components 1, 2, 6, 7 is alsoachieved, which can be a very desirable feature in certain magnetsystems 3.

Moreover, the invention teaches that additional flat multipole magnetsystems 3 can be manufactured, like the checkerboard-pattern magneticsurface 3 illustrated by way of example in

FIG. 12. Flat magnet systems 3 as claimed by the invention can also beused to construct three-dimensional magnet bodies 3, such as themagnetic scale 12 illustrated in FIG. 4, for example. The invention alsoteaches that the individual magnetic components 1, 2, 6, 7 can bereleased from the corresponding magazine 40 and then stacked to form athree-dimensional magnetic body 3.

Nomenclature:

-   1 Individual magnetic component-   2 Individual magnetic component-   3 Magnet system-   4 Magnet ring-   5 a, b End surface-   6 Individual magnetic component-   7 Individual magnetic component-   8 Magnet strip-   8 a, b, c, d Magnet strip-   9 a, b End surface-   10 Carrier-   11 Recess-   12 Magnetic scale-   13 a, b End surface-   14 a, b Transverse side end-   15 Step-   16 a, b Lateral surface-   17 a, b Lateral surface-   18, 18′ Frame-   19 Injection compression tool-   20 Top tool half-   21 Bottom tool half-   22 a, b Closing stop-   23 Base plate-   24 Mold insert-   25 Cavity-   26 Magnetizable material-   27 Injection channel-   28 Injection Up-   29 Injection nozzle-   30 Bubble-   31 Wafer-   32 Group with individual magnetic components-   33 Casting pan-   34 Molding material-   34 a Two-component resin-   35 Vacuum retaining plate-   36 Flashing-   37 Lateral surface-   38 Magnetizing device-   39 Coil-   40 Magazine-   41 Assembly robot-   42 Support plate-   43 Supporting ram-   44 Motor cover-   45 Guide pins-   46 Adhesive layer-   47 Assembly plate-   48 Reference marking-   49 Additional reference marking-   50 Magazine-   51 Expulsion ram-   51 a Expulsion pins-   52 External shape-   53 Base surface

1. A magazine for a plurality of magnetic components, comprising: themagazine, wherein the magazine is made of a hardening molding materialwhich encompasses the individual magnetic components made ofmagnetizable material only on portions of their outer surfaces, wherebythe individual magnetic components are located in the magazine at somedistance from one another and are all magnetized in the same direction.2. A magazine according to claim 1, wherein the individual magneticcomponents are magnetized along their longitudinal or transversedimension.
 3. A magazine according to claim 2, wherein the individualmagnetic components are made of a plastic-bonded rare-earth magneticmaterial.
 4. A magazine according to claim 3, wherein the individualmagentic components are made of a rare-earth magnetic materialcontaining NdFeB or SmCo.
 5. A magazine according to claim 3, whereinthe magazine has a disc-shaped or strip-shaped outer contour.
 6. Amagazine according to claim 5, wherein the individual magneticcomponents have the external shape of a circular ring segment or arectangular solid.
 7. A magazine according to claim 6, wherein moldingmaterial is located between two neighboring individual magneticcomponents.
 8. A magazine according to claim 6, wherein there is atleast one recess between two neighboring individual magnetic components.9. A magazine according to claim 6, wherein molding material and atleast one recess are located between two neighboring individual magneticcomponents.
 10. A magazine according to claim 1, wherein the individualmagnetic components are made of a plastic-bonded rare-earth magneticmaterial.
 11. A magazine according to claim 1, wherein the magazine hasa disc-shaped or strip-shaped outer contour.
 12. A magazine according toclaim 1, wherein the individual magnetic components have the externalshape of a circular ring segment or a rectangular solid.
 13. A magazineaccording to claim 1, wherein molding material is located between twoneighboring individual magnetic components.
 14. A magazine according toclaim 1, wherein there is at least one recess between two neighboringindividual magnetic components.
 15. A magazine according to claim 1,wherein molding material and at least one recess are located between twoneighboring individual magnetic components.
 16. A magazine according toclaim 1, wherein the individual magnetic components are made of arare-earth magnetic material containing NdFeB or SmCo.